Three lines of defense -- teachers, school guards and administrators -- all failed the day autistic teen Avonte Oquendo disappeared from school, a special commissioner said about his investigation.

Special Commissioner Richard Condon said all three failed to do what they were supposed to when a child goes missing from school. He commented Thursday after releasing a report that detailed a series of shortfalls and circumstances that contributed to the teen running out of the school unnoticed last October.

Among the failures the day he went missing: Avonte Oquendo's mother told his teacher that the autistic teen was prone to running and needed one-on-one supervision, but that information was never shared with school administrators.

The survey sent home by Avonte's teacher and filled out by his mother was the only indication the school had of his tendency to run away, according to the report.

But that was not the only contributing factor. The staff members who escorted Avonte and other students from the cafeteria were distracted by other students and didn't realize he was missing until later. And one school guard was on break, so the lone remaining guard couldn't leave her desk even when she saw Avonte running down the hall.

A principal refused an initial request for a soft lockdown, and didn't have the password for the video system, delaying the viewing of security footage that showed Avonte leaving unsupervised.

Avonte's mother, Vanessa Fontaine, said Thursday "there's a lot of anger" after reading the report.

"Answers? We don't have any," she told reporters. "We have no closure. There's no closure for us."

The report by the Special Commissioner of Investigation is being sent to prosecutors.

Avonte's teacher had sent home an informal survey to parents asking for more information about the parents. In it, Avonte's mother wrote: "Safety concerns -- please make sure you keep an eye out he likes to run. Need 1-1 supervisor will leave the building."

Despite this information, Avonte wasn't given one-on-one supervision. The teacher shared his mother's concerns with aides in her classroom, but not with school administrators. Other staff who escorted Avonte the day he left school didn't know.

The report details Avonte's last moments in the school before he slipped away:

He was in the cafeteria for lunch, then was being escorted with about 11 other students to a technology room.

Three adults were escorting the kids, but one broke away to deal with an unruly student. Another told investigators that he stayed with a student who was rushing ahead of the others. The third said he was focused on a student who was "fairly aggressive."

When the last adult arrived in the technology room, she counted the students and realized Avonte was missing. One of the teachers went back into the hallway to look for him. According to surveillance video, that was 16 minutes after he was last seen with the adults.

The school had two guards -- school safety agents who are employed by the NYPD -- but did not have a supervising guard. One guard was on break when Avonte ran by the front desk post, the report said. The remaining guard called out to him, but he didn't stop and she couldn't leave the desk unmanned, the report said.

The guard was also distracted with a parent who was picking up his sick child, the report said.

That guard thought Avonte had run upstairs and didn't realize he left the building, according to the report. She later closed the door where Avonte had left.

The report doesn't answer the question of who initially left the door open. A man was seen on surveillance video exiting the door without closing it behind him. He remains unidentified.